1. Field of the Invention
The present invention relates to liquid phase sintering processes. More specifically, the present invention relates to a process for liquid phase sintering in an open air environment at standard temperatures and pressures.
2. Description of the Related Art
Sintering is a process that is primarily used to form alloy materials from a powder precursor mixture. Liquid phase sintering is a sintering process that liquefies one of the powders by heating the mixture to the melting temperature of the powder to be liquefied. Present techniques for liquid phase sintering of ternary alloys are performed in a hydrogen environment in order to reduce oxides thereby decreasing porosity and increasing the density.
An example of such a technique is disclosed in Bose, U.S. Pat. No. 5,863,492 for a Ternary Heavy Alloy Based On Tungsten-Nickel-Manganese which was originally filed in 1991. The Bose Patent discloses a process for manufacturing a kinetic energy penetrator at a sintering temperature of 1100.degree. to 1400.degree. C. in a dry hydrogen environment. The Bose Patent discloses densities that are 96% of the theoretical density.
Another example is Rezhets, U.S. Pat. No. 5,098,469 for a Powder Metal Process For Producing Multiphase Ni--Al--Ti Intermetallic Alloys, which was filed in 1991. The Rezhets Patent discloses a four step sintering process that includes degassing, reduction of NiO, homogenization and liquid phase sintering.
Yet another example is Kaufman, U.S. Pat. No. 4,092,223 for Copper, Coated, Iron-Carbon Eutectic Alloy Powders, which was filed in 1976. The Kaufman Patent discloses a pre-compaction, liquid phase sintering process that is performed in a hydrogen environment.
What is needed is a method to lower the processing cost of manufacturing a high density multiple component material that may be shaped for various applications.